1. Field of the Invention
The present invention relates to a method, apparatus for receiving information and medium which can be used, for example, for receiving information transmitted from an information transmitting apparatus or the like over a digital broadcasting system, a public switched telephone networks and the like.
2. Description of the Related Art
Information conventionally, information such as animation, still images, speech, characters and/or programs has been exchanged utilizing a public switched telephone network as in the case of the Internet or a personal computer communication. However, both of the Internet and the personal computer communication employ a method wherein a receiver of information accesses an information service provider (in short, ISP), and selects and acquires (downloads) required information from the storage apparatus at the ISP and wherein the receiver can not acquire any information without taking any action on the ISP. That is, information can not be acquired through simple operations like selecting a channel as in the case of a common television broadcast. Such an information communication system involving operations at the end of a receiver can not be used as information communication means for advertising and public announcement.
In order to solve such a problem with multi-media information communication, information communication systems have recently been proposed wherein an ISP accesses a multiplicity of receivers for whom the information is intended over a public switched telephone network to send the information to the receivers and to accumulate it at the receivers' sides whether or not the receivers (homes) need the information and wherein each receiver selects displaying operations on the data storage apparatus (data receiving apparatus) to display necessary information on a screen through operations similar to, for example, those for selecting a television broadcast channel.
As a result of the progress of digital techniques, research and development are under way in the broadcasting industry toward digital broadcasting systems in which various kinds of information including broadcast signals are digitized. Known systems of such a type include integrated services digital broadcasting (ISDB) systems. In an ISDB system, multi-media information is digitized and is transmitted in an integrated and multiplexed form. When various kinds of information are integrated and multiplexed, additional information to be used as control information at the receivers' sides can be simultaneously transmitted in addition to such information.
Therefore, the use of the system as described above will make it possible to realize services to transmit various kinds of information such as news, sports news, weather forecasts, leisure information and program-related information.
However, the above-described configuration results in a problem in that a user can not efficiently find desired information by looking up the information on a receiving apparatus when the communication capacity of the public switched telephone network increases and when an enormous amount of information is transmitted utilizing means such as digital broadcasting that inherently employs a wide band. Meanwhile, an ISP adds a key word to information to be transmitted or transmits transmission schedules in advance to satisfy a need to allow users to look at the information continually. Japanese Patent Application Laid-Open (JP-A) No. 8-263410 has proposed a method in which a receiver specifies a key word for required information and selects the information by collating the key word which has been added to received information with the specified key word. However, using the received key word alone leaves a problem in that a receiver will be reluctant to look at information other than the specified information and will therefore have less opportunity to discover new information and in that a provider can not expect an increase in the number of users.
Meanwhile, increase in the power consumption of receiving terminals has recently become a problem and users have an increasing need for suppressing the power consumption of their receiving apparatuses during transmission of information unnecessary for them. Conventional receiving apparatuses have had a problem in that such an increase in power consumption can not be suppressed.